RHEL 6 / 7 : ntp (RHSA-2016:1141)

high Nessus Plugin ID 91420

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Synopsis

The remote Red Hat host is missing one or more security updates for ntp.

Description

The remote Redhat Enterprise Linux 6 / 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2016:1141 advisory.

The Network Time Protocol (NTP) is used to synchronize a computer's time with another referenced time source. These packages include the ntpd service which continuously adjusts system time and utilities used to query and configure the ntpd service.

Security Fix(es):

* It was found that when NTP was configured in broadcast mode, a remote attacker could broadcast packets with bad authentication to all clients. The clients, upon receiving the malformed packets, would break the association with the broadcast server, causing them to become out of sync over a longer period of time.
(CVE-2015-7979)

* A denial of service flaw was found in the way NTP handled preemptable client associations. A remote attacker could send several crypto NAK packets to a victim client, each with a spoofed source address of an existing associated peer, preventing that client from synchronizing its time. (CVE-2016-1547)

* It was found that an ntpd client could be forced to change from basic client/server mode to the interleaved symmetric mode. A remote attacker could use a spoofed packet that, when processed by an ntpd client, would cause that client to reject all future legitimate server responses, effectively disabling time synchronization on that client. (CVE-2016-1548)

* A flaw was found in the way NTP's libntp performed message authentication. An attacker able to observe the timing of the comparison function used in packet authentication could potentially use this flaw to recover the message digest. (CVE-2016-1550)

* An out-of-bounds access flaw was found in the way ntpd processed certain packets. An authenticated attacker could use a crafted packet to create a peer association with hmode of 7 and larger, which could potentially (although highly unlikely) cause ntpd to crash. (CVE-2016-2518)

The CVE-2016-1548 issue was discovered by Miroslav Lichvar (Red Hat).

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL ntp package based on the guidance in RHSA-2016:1141.

Plugin Details

Severity: High

ID: 91420

File Name: redhat-RHSA-2016-1141.nasl

Version: 2.17

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 6/1/2016

Updated: 11/4/2024

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.8

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

CVSS Score Source: CVE-2016-1548

CVSS v3

Risk Factor: High

Base Score: 7.2

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:ntp-doc, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:redhat:enterprise_linux:ntp, p-cpe:/a:redhat:enterprise_linux:ntp-perl, p-cpe:/a:redhat:enterprise_linux:ntpdate, p-cpe:/a:redhat:enterprise_linux:sntp

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 5/31/2016

Vulnerability Publication Date: 1/6/2017

Reference Information

CVE: CVE-2015-7979, CVE-2016-1547, CVE-2016-1548, CVE-2016-1550, CVE-2016-2518

CWE: 20

RHSA: 2016:1141

Detections

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